Piston for an internal combustion motor



May 29, 1934. Q LONG 1,960,313

PISTON FOR AN INTERNAL COMBUSTION'MOTOR Filed Dec. :50, 1929 Patented May 29, 1934 PATENT OFFICE PISTON FOR AN INTERNAL COMBUSTION MOTOR Elmer 0. Long, Detroit, Mich.

Application December 30, 1929, Serial No. 417,284

10 Claims.

This invention is a furthering of the improvements or principles disclosed in mypending applications for Letters Patent Serial Nos. 339,892,

522,974 and 602,660 filed November 22, 1919,

November 21, 1921 and November 22, 1922 respectively, on pistons for internal combustion motors, this invention pertaining to a differently constructed piston and also having means for tending to draw opposing portions of the piston skirt inwardly.

Another object of the invention is in constructing the piston skirt of a pair of opposing sections and of securing each section to the outer end of a respective pin boss for providing means of directing the thermal expanding forces from the head of the piston to the skirt sections.

Other and further objects will appear in the specification and be specifically pointed out in the appended claims, reference being had in the accompanying drawing, exemplifying the invention, and in which:

Figure 1 is a transverse vertical section taken through this improved piston on the line II of Fig. 3.

Figure 2 is a transverse vertical section taken approximately on the line II-II of Fig. 1.

Figure 3 is a horizontal section taken approximately on the line IIIIII of Fig. 1.

Figure 4 is an inverted horizontal section taken approximately on the line IVIV'of Fig. 2.

With reference to the accompanying drawing 1 designates the head of a piston having the packing ring grooves 2 formed in the side wall r 3 of the head, and formed integral with and depending from gpposing sides 3 of the head is a leg 5 of which there aTre a pair and extending inwardly from each leg is a pin boss 4.

Extending across the piston head 1 and formed integral with the head and the side wall 3 is a pair of ribs 6, said ribs being disposed parallel to the pin bosses 4. and extending downwardly from each end of a respective rib is a depending part 7, each part '7 being formed integral with respective legs 5 and respective pin bosses 4 as shown in Figs. 1 and 2.

Extending from opposing sides of respective pin bosses 4 is a transversely disposed portion 8 of respective webs 9 which underengage respective bosses 4, each of said web portions 8 uniting with the piston skirt 10 on respective thrust sides 11 of the piston skirt adjacent a respective slot 12 which is 'cut or formed in each thrust side 11. The upper portion of each of'the web portions 8 are each united with a depending part 7 of respective ribs 6 as shown at 18 in Fig. 2.

The piston head 1 is separated from the skirt 10 by a transverse annular gap or slot 13, the pair of slots 12 being disposed longitudinally and extending from the open end 14 of the piston to the annular gap 13 as shown in Figs. 1 and 2.

The body portions proper of each of the legs 5 are each separated from the skirt 10, each of said legs however being united with a respective thrust side 11 of the skirt by a vertical strip or portion 15, said strips extending from the head 1 to the bearing 16 of each pin boss 4, and whereas each pin boss at its lower end is united with the skirt by a strip or portion 17.

In the use of a piston of this improved charac ter when the piston is mounted in an internal combustion motor, the piston head 1 on account of receiving the propulsive thrusts from the forces caused by the combusting or exploding of the fluid charges in the upper end of the cylinder, will become highly heated by reason of the thermal condition in the cylinder, and the heat will travel down the walls 3 thereof and down the legs 5 to the pin bosses 4 and across the strips or portions 15 and 17 to the pin boss sides of the piston and in which the heat will be transferred circumferentially along the skirt wall in the directions of the arrows 22 (Fig. 3) towards the' longitudinal slots 12. This heating of the parts of the piston just described will obviously create expansion thereto and in which the piston head is increased in diameter but as the head is smaller in diameter than the skirt 10 the periphery thereof in which the packing ring recesses are disposed will not seize the cylinder wall. As the piston head 1 is expanded, the legs 5 will consequently be moved outwardly from one another by expansion of the head but as the pin boss sides 19 of the piston are relieved as designated at 20, clearance is therefore provided so that the skirt on the pin boss sides will not seize the cylinder wall. As the heat transfer to the skirt is through the portions 15 and 17, the heat and expanding forces thereof when applied to the skirt, will travel in the directions of the arrows 22 towards the slots 12 and the skirt united ends of the web portions 8 will be forced to be moved therewith, and as said web portions 8 are extended from respective pin boss sides, said web portions 8 will serve as tying or anchoring members to the thrust side sections 21, and the ends of said sections adjacent respective slots 12 will be drawn inward.

This drawing inward of the sections 21 tends to prevent the thrust sides 11 of the pistonfrom expanding too far outwardly when the piston becomes highly heated by reason of the web portions 8.0n each side of the pin bosses 4 tending to swing inwardly on the imaginary fulcrum provided along the place of joining of the web portions 8 to the pin bosses. Obviously when the piston becomes cool the contracting forces on the skirt wall will travel in a direction opposite to the arrows 22 and in which the web portions 8 will tend to return to their normal positions. I

A piston of this improved character can be made to a proper fit with respect to it being mounted in a cylinder having a proper working relation with the cylinder when the piston cylinders are cold and when the cylinder and piston become heated by reason of the firing impulses in the cylinder and on the piston, the construction of the piston is such wherein the piston will still retain the proper working relation with the cylinder when the piston and cylinder are in highly heated conditions, this improved construction providing for an eflicient and durable piston.

While a preferred embodiment of the invention is shown, it is to be understood that various changes, size, shape and arrangements of parts, may be resorted to without departing from the spirit and scope of the invention of the claims hereto.

What I claim is:

1. A piston having a head and a skirt separated from the head, pin bosses depended from the head interiorly of the skirt, a slotting formed in the skirt on the thrust sides thereof, and a web extending from each side of a respective pin boss to respective thrust sides of the skirt, each of said pin bosses being separated from the skirt except through the center of their outer ends.

2. A piston having a head and a skirt separated from the head, pin bosses depended from the head interiorly of the skirt, a slotting formed in the skirt on the thrust sides thereof, and a web extending across each pin boss to opposing thrust sides of the skirt, each of said pin bosses being separated from the pin boss sides of the skirt except through the center of their outer ends.

3. A piston having a head and a skirt separated from the head, pin bosses depended from the head interiorly of the skirt, a slotting formed in the skirt on the thrust sides thereof, and a web extending from each side of a respective pin boss to respective thrust sides of the skirt, each of said pin bosses having a portion for tying it to a respective pin boss side of the skirt, the portions of said webs on each side of said pin bosses being adapted to swing inwardly towards each other at their outer ends when the piston is expanded.

4. A piston having a head and a skirt separated from the head, pin bosses depended from the head interiorly of the skirt and being free from engagement with the skirt except through their central portions, a slotting formed in the skirt on the thrust sides thereof, and. a web extending from each side of a respective pin boss to respective thrust sides of the skirt, the portions of each web on each side of said pin bosses being inclined towards each other at their outer ends.

5. A piston having a head and a skirt, a pair of legs extending downwardly from said head and being connected to the skirt by a centrally disposed longitudinal strip, a pin boss extending from each leg interiorly of said skirt, said skirt having a longitudinally extending slot formed in each thrust side thereof, and a web extending from each side of a respective pin boss to respective skirt sides adjacent respective slots.

6. A piston having a head and a skirt, a pair of legs extending downwardly from said head within said skirt, a pin boss extending from each leg interiorly of said skirt, said skirt having a longitudinally extending slot formed in each thrust side thereof, and a web extending from each side of a respective pin boss to respective skirt sides adjacent respective slots, each of said pin bosses being disconnected from the skirt except through the central portions of their outer ends on the pin boss sides of the skirt.

7. A piston having a head and a skirt, pin bosses depended from the head interiorly of the skirt, said skirt on each thrust side thereof having a longitudinal slot extending from the open end of the piston, and a web extending from each side of a-respective pin boss to respective thrust sides of the skirt, each of said pin bosses at their outer ends being free from engagement with a respective pin boss side of the skirt except through a vertical plane including their axes.

8. A piston having a head and a skirt, a.pair of legs extending downwardly from the head interiorly of the skirt and spaced therefrom, a pin boss extended inwardly from each leg, each of said legs having an intermediately disposed 10ngitudinal strip connecting said legs and pin bosses to the pin boss sides of the skirt, said skirt having a longitudinally extending slot formed in each thrust side thereof, and a web extending from each side of a respective pin boss to respective thrust sides of the skirt adjacent respective slots.

9. A piston comprising a head, a skirt separated from said head, said skirt being longitudinally split at the thrust sides thereof, means for transferring heat from the head to the wrist pin sides of said skirt, and means engaging said skirt adjacent the splits for diverting the split edges inwardly upon circumferential expansion thereof away from said first means.

10. A piston having a head and a skirt separated therefrom, a pair of legs depended from the side Wall of the head within the skirt and spaced therefrom, each leg carrying a pin boss and said legs being connected to the skirt above the pin bosses by a relatively narrow longitudinal portion, said skirt being slotted.- to provide flexibility thereto, and resilient webs from the pin bosses to the thrust sides of the skirt.

1 ELMER C. LONG. 

